1. Field of the Invention
The present invention relates to etherified oxacalixarenes which are useful for promoting adhesion of cyanoacrylate-based compositions to porous or deactivating surfaces, to a process for their preparation and to adhesive compositions comprising them.
2. Description of the Related Art
Various accelerators have been proposed for improving the curing time of cyanoacrylate-based adhesives on wood, paper or substrates with porous or deactivating surfaces. In general, these adhesive compositions require an accelerator which sequesters alkali metal cations. U.S. Pat. No. 4,171,416 suggests the use of crown ethers, which are macrocyclic molecules capable of complexing with a metallic ion. However, these compounds are highly toxic and therefore unsafe to use.
In U.S. Pat. No. 4,170,585, there are described cyanoacrylate compositions in which certain polyethylene glycols or poly(ethyleneoxy)-functional surfactants act as wood bonding accelerators. Such compounds, however, have the reported disadvantage that they tend to contain water and other difficult to remove substances which spontaneously initiate polymerization of the cyanoacrylate monomer.
U.S. Pat. No. 4,377,490 discloses mixtures of aromatic and aliphatic polyols and polyethers said to improve initial strength of cyanoacrylate wood bonding products.
U.S. Pat. No. 4,386,193 discloses certain 3 or 4 arm polyol podand compounds as alternatives to crown-ether accelerators.
Japan Kokai Tokkyo Koho 82-70171, suggests the use of certain polyorganosiloxane compounds which include polyether substituents as additives for wood bonding cyanoacrylate compositions. Chem. Abstracts, 97 145913n reports the use of a hydroxy-terminated poly(dimethyl-siloxane) in fast bonding cyanoacrylate compositions.
DE-OS No. 3,006,071 discloses certain furan derivatives as co-accelerators with crown ethers in cyanoacrylate compositions.
U.S. Pat. No. 4,556,700 Harris et al describes the use of certain calixarene compounds as accelerators in cyanoacrylate compositions. Irish patent application No. 819/86 Loctite (Ireland) Limited describes further calixarene compounds including polymer-bound calixarene compounds which are also useful for this purpose.